Not much to show on this game besides a trailer anyway for those who missed it here we are. Kotaku says Spring 2016 but i assume its a placeholder atm
The trailer showcased a country in the midst of tyranny and revolution. Your character this time around is Emily Kaldwin, the rightful heir to the throne in the original game. She has a blue organic grappling hook that she can use to quickly scale buildings. Bethesda revealed that you can also play as Corvo, the hero from the first game. The trailer came to a head when Emily infiltrated a home and went to assassinate her target, who was flanked by a pair of robotic guards. The trailer also had other nods to the first game, such as The Outsider who gave Corvo his powers, as well as Corvo's iconic mask. Bethesda and Arkane promised that you can play through the entire game without killing anybody.
Here's the official story summary from Bethesda:
Dishonored 2 is set 15 years after the Lord Regent has been vanquished and the dreaded Rat Plague has passed into history. An otherworldly usurper has seized the throne from Empress Emily Kaldwin, leaving the fate of the Isles hanging in the balance. As either Emily Kaldwin or Corvo Attano, travel beyond the legendary streets of Dunwall to Karnaca – a once-dazzling coastal city that holds the key to restoring Emily to power. Armed with the mark of the Outsider and powerful new supernatural abilities, hunt down your enemies and forever alter the fate of the Empire.